Industrious beetle is the one attacking pecan trees

Friday

Oct 19, 2012 at 12:01 AMOct 19, 2012 at 3:28 PM

Question: Everyday we pick up branches that have fallen off of our pecan tree. My husband says it is because of the squirrels. Is there any way to stop them from doing this? Answer: Squirrels are very industrious and mischievous. But the blame for this activity goes to an insect. The pecan twig girdler is the culprit. These beetles are very active during the month of August and September. Using their chewing mouth parts, they cut a very clean circle around the branch. This actually results in girdling the branch and cutting off all water and nutrient flow. As a result, the tip of the branch dies. The clever female will deposit her eggs under the bark of the dead branch. Later in the fall of the year the branch finally hits the ground. The young hatch out and stay within the branch over the winter months. There are different species of twig girdlers that attack persimmon, hickory, and many other forest tree species. It is impractical to spray large pecan trees, therefore the best management strategy is to pick up the limbs and burn them if you live in the county. City residents should put them in the garbage or for curbside pickup. This insect is not that injurious to older pecans. For younger trees, I would spray Sevin weekly during the month of August.

Question: I have some property that has an old grove of black walnut trees. Can I plant the walnuts that are falling now with hopes of getting new seedlings? Answer: I was fortunate that the county agents before me were hoarders. When new U.S. Department of Agricultural publications arrived monthly, they had the foresight not to discard many of the older ones. I inherited hundreds of publications dating back to the early 1900s. I even had one dated in the mid-1930s on how to successfully plant kudzu on your farm. The fate of that publication rests now with Roger Cobb, my successor. One publication I have is “Growing Walnut for Profit,” published in 1945. This publication recommends planting the nuts in either the fall or spring. You do not need to remove the hull prior to planting. Spring planting is best if you store the nuts in a cool and moist site. There is a nice design of a planting bed with the nuts in layers of sand waiting spring planting. Regardless, dig your hole 2 inches deep and plant 2 nuts per hole either now or in March. Fall plantings are at a higher risk of being disturbed by hungry animals. Next week, I will tell you how to protect them from squirrel and other rodents by using a very old planting and ingenious technique.

Question: Our house has been invaded with masses of very small brown bugs with a square back. What are these insects? Answer: People are always asking me where do I get all the questions I answer each week. My best source is from my network of people I worked with over the years as a county agent. Although I was assigned Alamance County, I often crossed the line (not far). In this case, Charles Gregory, in southern Caswell County, gets the credit for being the first to let me know that the kudzu bugs are appearing in our area. They have been feeding on soybeans instead of kudzu. As soybeans begin to lose their leaves and from harvesting, the kudzu bugs are taking flight. They gather in masses just like the Asian ladybird beetles that were supposed to eat aphids on pecans in Georgia. Needless to say, they will be aggravating and you will be frustrated, since controlling them is next to impossible. They will be just like the price of gas. Their populations will rise and fall regardless of whom you elect for president or any other political office.

HAZARDOUS WASTE DISPOSAL TODAY Don’t forget to take your household hazardous waste to the annual disposal day on Stone Quarry Road in Haw River. They will be open from 9 a.m. until 1 p.m. today only.

Rett Davis is the retired Director of the Alamance County Cooperative Extension Service and is a certified arborist. You can send your questions to him at Rett_Davis@ncsu.edu

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